Antimicrobial Activities of Tribulus terrestris L. on Selected Pathogenic Microorganisms

The antimicrobial effect of aqueous, acetone and chloroform extracts of leaf, stem and root of Tribulus terrestris on three bacteria namely Escherichia coli, Lacto bacillus and Bacillus cereus were determined using agar well diffusion and paper disk methods. In Escherichia coli the widest zone of inhibition (33.6 +/- 1.05mm) was demonstrated by the acetone leaf extract (80 mu l). In Bacillus cereus the widest zone of inhibition (23.6 +/- 0.88mm) was demonstrated by the acetone leaf extract (80 mu l) while the value dropped to 22.5 +/- 0.12 and 20.4 +/- 0.02 mm for chloroform stem and chloroform root extracts respectively when tested against the same organism. In Lacto bacillus the widest zone of inhibition (31.3 +/- 1.20mm) was demonstrated by the acetone leaf extract (80 mu l) followed by 29.3 +/- 0.94mm and 28.5 +/- 1.33 mm for chloroform leaf and acetone root extracts respectively. There were no inhibitions in chloroform root extracts. This study revealed that the Tribulus terrestris demonstrated strong inhibitory effect on the test organisms than T. terrestris. The results therefore established a good support for the use of T. terrestris in traditional medicine